Door stop



March 20, 1962 W BASINGER 3,025,559

DOOR STOP Filed Aug. 24, 1959 i,Unite diaree are 3,025,559 DOOR STOP Joseph W. Basinger, 2246 Ridgernont, Hollywood, Calif. Filed Aug. 24, 1959, Ser. No. 835,606 3 Claims. (Cl. ld-SS) This invention relates to door stops and, more particularly, to a door stop which magnetically retains the door in its fully open position against an adjacent wall as well as, at the same time, preventing the door or door knob from contacting the wall.

There are many applications in which it is desirable to hold the door open against undesired closing by relatively small forces such as lby drafts while permitting it to be closed by relatively large forces. A relatively large force is provided by the individual desiring to close the door. For such applications, it is necessary to yieldably engage the door when it is swung to its fully open position. Mechanical door stops for engaging the door when it is fully` opened have generally been unsatisfactory because the repeated impact of the door against the stop due to successive door openings destroys the alignment of the various components of the door stop to prevent the door stop from operating properly. Magnetic door stops have heretofore also been unsatisfactory because the repeated impact resulting from the door openings destroys the alignment of the components and often breaks the magnet which is brittle. Furthermore, relatively small components have been used in magnetic door stops so that a relatively small engaging force has been produced by the magnetic components.

In a specic illustrative embodiment of this invention, a magnetic door stop is provided which includes a ceramic magnet which is fully enclosed by a holder formed of a plastic material. The magnet is sandwiched between two substantially rectangular steel plates which increase the magnetic tlux coupled from the magnet to a steel washer supported on the door. The two steel plates extend from the plastic holder and the steel washer contacts only the steel plates when the door is opened. The holder, including the magnet and steel plates, is supported on the end of a coiled cushion spring which is mounted on the wall adjacent to the door. When the door engages the two steel plates extending from the holder, the door-stop readily aligns due to the flexibility of the coiled cushion spring. The steel plates have a dual function in that in addition to increasing the engaging force between the magnet and the washer mounted on the door, they also function to protect the magnet against breakage. The magnet is actually not contacted by the steel washer when the door is fully opened be p cause the two steel plates extend from the front of the holder whereas the magnet is fully surrounded by the plastic holder.

Further features of this invention relate to provision of a rigid assembly for supporting and enclosing the magnet. The magnet is imbedded in the plastic holder and cannot move relative to the holder or to the steel plates in the holder.

Still other features of this invention relate to aligning the two steel plates vertically to reduce the required rotation of the plastic holder and the plates in a horizontal direction when the steel plates are contacted by the door.

Still further features of this invention relate to the provision of apertured steel plates wherein the apertures are lled with plastic when the holder is molded so as to lock them in position.

Further features and advantages of this invention will become apparent upon lconsideration of the following description when read in conjunction with the drawing wherein:

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FIGURE 1 is a pictorial view of the magnetic door stop of this invention;

FIGURE 2 is a partial sectional side View of the magnetic door stop of this invention;

FIGURE 3 is a sectional view taken along lines 3 3 of FIGURE 2; and

FIGURE 4 is a pictorial View of the screw member which engages the wall and which also supports the coiled cushion spring of the magnetic door stop of this invention.

Referring to the drawing, the door stop assembly includes a magnetic door stop `designated generally at 8, which is mounted on a baseboard 2.5. The baseboard 25 forms part of a wall, the rest of which is not shown. The door stop 8 engages a contact member 9 which is screwed on the back of a door 24. The door stop assembly includes the door stop 8 and the contact member 9. The member 9 has a viiat headed screw 22 `and Aa circular steel washer 2t) which is supported by the screw 22 against the door 24.

The magnetic door stop 3 includes a screw member 19 at one end and a holder 16 at the other end. The screw member 10 has two oppositely extending threaded extensions Il and l2. The extension Il .is tapered and is utilized to mount the door stop 8 on the baseboard 25 adjacent to the movable door 24. The .screw member l0 may be a single metallic piece which when manufactured is formed by a casting over a conventional screw as depicted in FIGURE 2. The threaded extension l2 supports one end of a coiled cushion spring l5. The cushion spring l5, as illustrated in FIGURES l and 2 is an extended coil spring so that a force at one end causes it to compress and function as a shock absorber. The spring l5', moreover, is flexible in that it may be distorted transversely with respect to its longitudinal axis.

The right end of the spring l5 supports a holder 16 which may be made of a polyethylene plastic. A collar 16A of the holder I6 is formed as by molding over the right end of the coiled cushion spring l5. rl`he plastic holder I6 supports a rectangular shaped magnet 3i) and two steel plates i7 and l. The magnet Si), which may be a ceramic magnet, for example, of the type referred to as lndox and manufactured by the Indiana Steel Company, is fully enclosed by the plastic holder i6 and may be made from a suitable ferromagnetic material. The plastic surrounding the magnet has a dimension at least of 1/s of an inch on all sides except on the front face 35 of the holder I6 where the thickness of the plastic may be 20 to 5i) thousandths of an inch. These specific dimensions for the thickness of the plastic are merely illustrative.

The two steel plates ll7 and IS sandwich the magnet 30 therebetween functioning both to concentrate the lines of llux from the magnet 30 through `the washer 2li, and to protect the magnet 3G from breaking upon the impact of the contact member 9 when the door 2.4 is opened. The ends of the steel plates, approximately 1/3 of an inch, extend from the face 3S of the plastic holder i6. As depicted in FIGURE l, the plates I7 and I3 are vertically aligned and spaced about 3,'/16 of' an inch apart. The height of the steel plates I7 and I8 is considerably larger than the distance therebetween, being approximately of an inch.

Each of the steel washers 17 and i8 has a notch 32 which is utilized to position the plates 17 and lit in the mold, not shown, utilized to make .the plastic holder i6. The washers 17 and I8 may also respectively have apertures 28 and Z9 which are filled with plastic during the molding process. The plastic in the apertures 28 functions as locking means to lock the steel plates 17 and 1g in position in the plastic holder 16. The steel plates I7 and 18 may also be slightly tapered tow-ard the face 35 of the holder 16 so that they are rigidly held in position -against the magnet 311. There is no possible movement between the steel plates 17 and 18 and the magnet Sti or between either the plates 17 and 18 and the magnet 30 and the plastic holder 16. The holder 16, the magnet 30 and the steel plates 17 and 18, in this manner form a rigid structure.

The steel plates 17 and 18 concentrate the lines of ux from the magnet 30 because they form low reluc- 'tance paths. When the washer 2d contacts the ends of the two steel plates 17 and 18, a very low reluctance path for the magnet 3d is provided without air gaps. Substantially all of the iiux passes through the low reluctance path formed by the plates 17 and 18 and the washer 20. The magnetic attractive force ybetween the door stop 3 'and the contact member 9 depends upon the number of lines of flux linking the magnet 311 and the washer 2t?. Because of -the concentration or" the linx through the plates 17 and 18, the engaging force of the door stop 9 is many times as great as when the magnet alone is utilized.

The turns of the spring 15 are tightly wound at each end and are loosely wound through a limited number of turns iat a position intermediate the ends as indicated at 40 in FIGURE 2. By providing the loose relationship 4t) between the limited number of turns, the spring 15 is able to cushion the torce exerted against the door stop 8 when the door moves against the stop. Furthermore, the spring is able to become pivoted easily in a horizontal plane so that both of the plates 17 and 1S are able to Contact the washer 20.

The `turns of the spring 15 at the end adjacent the extension 12 of the screw member 10 are provided with a rst diameter. The turns of the spring 15 at the opposite end are provided with a second diameter reduced with respect to the first diameter. Successive turns of the spring 15 at a position intermediate the ends and adjacent the loosely `disposed turns di) are provided with diameters progressively varying between the lirst and second diameters.

When the door 24 is opened, the washer 20 first engages the plate 17 and then the plate 18 because of the slight angle formed by the door 24 with the face 35 of the holder 16. As described above, the plates 17 and 18 are aligned vertically at a relatively small spacing from each other. The holder 16, therefore, requires only a small aligning rotation of the spring 15 in ta horizontal plane to become aligned with the end of the spring adjacent to the holder and to engage both of the plates 17 and 18. If the plates 17 and 18 are horizontally aligned instead of vertically aligned as shown in FIGURE 3, an increased amount of rotation of the spring 15 in the horizontal direction is required for Ithe two steel plates 17 and 18 to fully engage the washer 20.

When the door 24 is opened, the coiled spring 15, therefore, both cushions the impact and also bends to align the face 35 of the holder 16 with the washer 20. The impact on the ceramic magnet 3@ is cushioned by the coiled spring 15 in addition to being protected by the sandwiching plates 17 and 18 and the plastic holder 16. As described above, the plastic holder fully encloses the magnet 30 even at the face 35.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated bythe scope of the appended claims.

What is claimed is:

1. A door stop assembly for preventing a door from contacting ya wall -adjacent -to the door and also for retaining the door in its fully open position, including, a magnetic door stop adapted to be secured to the wall adjacent the door, and a contact member made of magnetic material adapted to be secured to the door in a position to contact said magnetic door stop when the door is fully opened, said door stop including a holder made of non-magnetic material, two plates of magnetic material supported in a spaced apart position by said holder, each of said two plates being vertically aligned `and having at least one aperture for engaging a portion of said holder whereby said plates are locked in position in said holder, and a permanent magnet sandwiched between sia-id two plates and fully enclosed by said holder for generating magnetic ilux through said plates and through said contact member when the door is fully opened, said holder being made of a non-magnetic material and including a portion between said two plates and extending over said permanent magnet, a fastening member engageable with the wall adjacent the door, and a coiled spring mounted on said fastening member for resiliently supporting said holder whereby said contact member is yieldably engaged by said door stop to cushion the impact of said contact member against said steel plates extending from said holder when the door is fully opened and to permit the disposition of both of said plates against said contact member.

2. A door stop assent-bly for preventing a door from contacting -a wall adjacent to the door, including, a spring formed from a plurality of helical turns tightly wound at iirst and second opposite ends and loosely wound through a limited number of turns at an intermediate position between the rst and second opposite ends of the spring to provide a cushioning against forces exerted against the spring; magnetic means supported by the spring, the magnetic means including a holderA made from a nonmagnetic material and provided with a collar extending over a limited number of turns in the spring at the iirst end of the spring, the magnetic means further including a pair of magnetizable plates disposed in spaced relationship within the holder and provided with a length to exfV tend from the holder :at the end of the holder removed from the spring, the magnetic means further including a permanent magnet disposed within the holder in sand-` wiched relationship to the pair of magnetizable plates and provided with a length shorter than that of the plates to obtain an extension of the plates beyond the permanent magnet; iirst means having an extension at a first end for receiving the second end of the spring to provide a support for the spring, having a threaded portion at a second end opposite to the lirst end to screw into the wall and hav# ing a portion intermediate the extension and the threaded portion to limit the movement of the lthreaded portion into the wall; and second means having a threaded portion at a irst end to screw into the door and having `an enlarged portion at a second end opposite to the rst end, the enlarged portion being formed from a magnetizable material to engage the pair of magnetizable plates for the formation of a closed magnetic circuit with the plates, the pair of magnetizable plates being provided with a vertical disposition and with apertures and the holder being provided with portions which extend into the apertures in the plates to hold the plates in fixed position within the holder.

3. A door stop assembly for preventing a door from contacting a wall adjacent to the door, including, a spring formed from a plurality of helical turns tightly wound at first and second opposite ends `and loosely wound through a limited number of turns .at an intermediate position between the rst and second opposite ends of the spring to provide a cushioning against forces exerted against the spring; magnetic means supported by the spring, the magnetic means including a holder made from a non-magnetic material land provided with a collar extending over a limited number of turns in the spring at the iirst end of the spring, the magnetic means further including a pair of magnetizable plates disposed in spaced relationship within the holder and provided with a length to extend from the holder `at the end of the holder removed from the spring, the magnetic means further including a permanent magnet disposed within the holder in sandwiched relationship to the pair of miagnetizable plates and provided with a length shorter `than that of the plates to obtain an extension of the plates beyond the permanent magnet; first means having an extension at a first end for receiving the second end of the spring to provide a support for the spring, having a threaded portion at a second end opposite to the rst end to screw into the Wall and having a portion intermediate the extension and the threaded portion to limit the movement of the threaded portion into the wall; and second means having a threaded portion at a rst end to screw into the door and having an enlarged portion at a second end opposite to the first end, the enlarged portion being formed from a magnetizable material to engage the pair of magnetizable plates for the formation of a closed magnetic circuit with the plates, the turns of the spring being provided with a rst diameter at the rst end of the spring and being provided at the end opposite to the iirst end with a second diameter reduced with respect to the rst diameter and progressively varying between the rst and second ends and the pair of mtagnetizable plates being provided with a vertical disposition and the pair of vertical plates being provided with apertures land the holder being provided with portions which extend into the apertures in the plates to hold the plates in fixed position within the holder.

References Cited in the le of this patent UNITED STATES PATENTS 2,240,035 Catherall Apr. 29, 1941 2,700,788 Hennelly Feb. 1, 1955 2,701,158 Schmitt Feb. 1, 1955 2,761,718 T001 Sept. 4, 1956 

